DERIVATIVE FINANCIAL INSTRUMENTS AND HEDGING ACTIVITIES (Details 8) (CAD) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2012	Dec. 31, 2011
Changes in net fair value of derivative assets and liabilities classified as Level 3 in the fair value hierarchy
Level 3 net derivative asset/(liability) at beginning of year	32	(24)
Total unrealized gains/(loss)
included in earnings	(69)	31
included in OCI	13	(41)
Purchases		8
Settlements		58
Level 3 net derivative asset/(liability) at end of year	(24)	32
Fair Value of Other Financial Instruments
Equity investments at carrying value	66	57
Preferred share investment \| Minimum
Fair Value of Other Financial Instruments
Cumulative dividends based on average yield of Government of Canada bonds, maturity period of bonds	10 years
Cumulative dividends based on average yield of Government of Canada bonds, spread over reference rate (as a percent)	4.30%
Preferred share investment \| Maximum
Fair Value of Other Financial Instruments
Cumulative dividends based on average yield of Government of Canada bonds, spread over reference rate (as a percent)	4.40%
Carrying value
Fair Value of Other Financial Instruments
Long-term debt	20,855	19,605
Carrying value \| Preferred share investment
Fair Value of Other Financial Instruments
Held to maturity preferred share investment	246	285
Fair value
Fair Value of Other Financial Instruments
Long-term debt	24,809	22,620
Fair value \| Preferred share investment
Fair Value of Other Financial Instruments
Held to maturity preferred share investment	580	580

Represents the percentage points added to the variable reference rate for the calculation of cumulative dividends.

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Represents the maturity period of the Government of Canada bonds that are used as the variable reference rate for the calculation of cumulative dividends.

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Represents the amount of gain (loss) recognized in earnings, arising from assets and liabilities measured at fair value on a recurring basis using unobservable inputs (level 3).

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Represents assets and liabilities, net, measured at fair value using significant unobservable inputs (level 3) which is required for reconciliation purposes of beginning and ending balances.

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No definition available.

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Purchases that have taken place during the period in relation to assets and liabilities measured at fair value and categorized within level 3 of the fair value hierarchy.

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Represents the settlements that have taken place during the period in relation to assets and liabilities measured at fair value and categorized within level 3 of the fair value hierarchy.

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No definition available.

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This item represents the aggregate carrying amount of all cost-method investments as reported on or included in the balance sheet. The original cost of the investments may differ from the aggregate carrying amount disclosed due to various adjustments such as: (i) dividends received in excess of earnings after the date of investment that are considered a return of investment and therefore recorded as reductions to cost of the investment, or (ii) a series of operating losses of an investee or other factors which may indicate that a decrease in value of the investment has occurred which is other than temporary and accordingly such decrease in value has been recognized.

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Amount of gain (loss) recognized in other comprehensive income, arising from assets, liabilities and financial instruments classified in shareholders' equity measured at fair value on a recurring basis using unobservable inputs (level 3).

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- Definition

This element represents the portion of the balance sheet assertion valued at fair value by the entity whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission. This item represents investments in debt securities which are categorized as held-to-maturity and that have scheduled maturities more than one year from the balance sheet date or operating cycle, if longer; such investments are normally measured at amortized cost (carrying value) unless circumstances indicate that the value to be recovered from the investment is less than its carried amount. The held-to-maturity category is for those securities that the Company has the positive intent and ability to hold until maturity.

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The fair value amount of long-term debt whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission.

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